The dot plot below shows the amount of time two random groups of students took to solve a math problem:

based on visual inspection of the dot plots, which of the following groups, if any, shows a greater average time required to solve the problem?

a. group x
b. group y
c. both groups show about the same average time.
d. no conclusion about average time can be made from the data.

Using pert, adam munson was able to determine that the expected project completion time for the construction of a pleasure yacht is 21 months, and the project variance is 4. a) what is the probability that the project will be completed in 17 months? b) what is the probability that the project will be completed in 20 months? c) what is the probability that the project will be completed in 23 months? d) what is the probability that the project will be completed in 25 months? e) what is the due date that yields a 95% chance of completion?